Improvement in watch-keys



R. S. MERSHON.

Watch Key.v Patented Nov. 24, 1863.

struction and operation of the same, reference Vthe parts very strong and durable, even in NITED STATES PATENT OEEICE.

RALPH S. MERSHON, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR 'IO HIMSELF AND JOHN M. HARPER.

IMPROVEMENT IN WATCH-KEYS.

Specification forming part of Letters Patent No. 40,726, dated November 24, 1863.

To all whom; it may concern:

Be it known that I, RALPH S. MERsHoN, of the city and county of Philadelphia, and State of Pennsylvania, have invented certain new and useful Improvements in Watch-Keys 5 and I do hereby declare the following tobe a full, clear, and exact description of the conbeing had to the accompanying drawings, making a part of this speciiication, in which- Figure l represents a view of a nished key. Fig. 2 represents the interior portions thereof. Fig. 3 represents the interior portion with the sleeve partially in section to show the shank passing through it. Fig. 4L represents the ordinaryratchetkey.

Similar letters of reference, where they occur in the separate gures, denote like parts in all the drawings.

Ratchet-keys for winding watches and other time pieces are well known; but theirconstruction hitherto has been too costly to admit of their coming into general use. The ratchet keys now used consist of reciprocating surfaces having teeth on both of their workingfaces, one surface being fixed andthe other being movable, and when in rest are held so by a spiral spring. When the key is turned in one direction, these reciprocating ratchets are at rest, but when turned in the opposite direction the movable ratchet revolves on its spindle and slides up the inclined surfaces of the teeth of the ixed ratchets. to be thrown v down and held at rest again by the spiral spring. The cost of such teeth, the neatness with which they must it to each other, their delicacy of construction, and their liability to wear or break at their points all tend to keep them out of general use. I substitute a pin for the fixed ratchet, and in the movable part of the key I form two teeth, diametrically opposite to each other, which are found to be abundant, because time-pieces are generally wound by half-turns, and there is consequently no need for more than one tooth for each halfturn. This construction enables me to make very small keys, and, besides, it avoids the expense-of making the parts of steel, which metal, in the former construction of ratchetkeys, is indispensable, and so simplifies and cheapens the key as to admit of its universal use.

To enable others skilled in the art to make and use my invention, I will proceed to describe the same with reference to the drawings.

The key, as shown at a, Fig. l, may be finished with such external ornament or appendage as may be desired, or may be plain, when so preferred. The spindle b may have the pod teeth, g, formed in it to correspond with the pin or pins in the spindle, there being one inclined or curved side, It, and one perpendicular side, i, to eachtooth, so that said'sleeve or movable part f may move up and down and turn around on and with said spindle b, as the case may be. On the upper end of the spindle there is acollar, j, and between said collar and the upper end of the sleeve f there is a spiral spring, k, encircling the spindle b, which spring in its normal condition holds the teeth and pins together, but which admits of the rising of the sleeve upon the spindle, as well as the turning of it, in the act of winding up the time piece.

It is obvious that the pin and teeth may be reversed without changing the character of the invention-that is to say, the pin or pins may be in or on the movable part, and the teeth. in or on the stationary part-and that two pins and two teeth are sufficient for the purpose, though more may be added, if desired.

I have represented in the drawings a key on a large scale, but design applying my invention to time-piece keys generally, small as well as large ones.

Having thus fully described my invention, what I claim in the construction of watchkeys, &c., as a substitution for the ordinary ratchet-teeth heretofore used in the movable and xed parts thereof, is-

A pin or pins in one part and two teeth in the other part, operating together in the manner and for the purpose substantiallyas described.

RALPH S. MERSHON. Witnesses:

HENRY HARPER, JAMES L. WHEELER. 

